In the present work the responses of beta-glucosidase in leaves of tomato p
lants subjected to various stress factors of both pathogenic (fungi, bacter
ia, viruses) and abiotic origin (heat shock) were studied. Biochemical and
cytochemical methods were applied, it was established that an increase of P
-glucosidase activity is induced uniquely by fungal pathogens. The cytochem
ical tests confirm the finding. Hence, the conclusion can be drawn that P-g
lucosidase response is a specific character of fungal pathogenesis in tomat
o; probably, the enzyme is involved in plant - fungi recognition. The data
are in accordance with our previous results on tobacco and wheat - stress s
timuli systems.